Is atmospheric oxidation capacity better in indicating tropospheric O3 formation?

● This study summarizes and evaluates different approaches that indicate O₃ formation. ● Isopleth and sensitivity methods are useful but have many prerequisites. ● AOC is a better indicator of photochemical reactions leading to O₃ formation. Tropospheric ozone (O₃) concentration is increasing in China along with dramatic changes in precursor emissions and meteorological conditions, adversely affecting human health and ecosystems. O₃ is formed from the complex nonlinear photochemical reactions from nitrogen oxides (NO_x = NO + NO₂) and volatile organic compounds (VOCs). Although the mechanism of O₃ formation is rather clear, describing and analyzing its changes and formation potential at fine spatial and temporal resolution is still a challenge today. In this study, we briefly summarized and evaluated different approaches that indicate O₃ formation regimes. We identify that atmospheric oxidation capacity (AOC) is a better indicator of photochemical reactions leading to the formation of O₃ and other secondary pollutants. Results show that AOC has a prominent positive relationship to O₃ in the major city clusters in China, with a goodness of fit (R²) up to 0.6. This outcome provides a novel perspective in characterizing O₃ formation and has significant implications for formulating control strategies of secondary pollutants.     

Comparative Assessment of the Effects of Livestock Grazing and Periodic Cutting on Steppe Plants of Tuva

A comparative study of the effects of heavy grazing load and periodic low cutting of above-ground phytomass on three plant species—Carex pediformis, Iris humilis, and Artemisia frigida—was performed in central Tuva in 1985–1989. Similar changes in the size of anatomical structures and ecophysiological characteristics of steppe plants were observed under the impact of both factors. They included signs of accelerated aging combined with adaptive reactions aimed at the most rapid development of shoots after the cessation of stress.     

Influence of Hydrologic Conditions of the Lower Ob Floodplain on Reproduction in Coregonids

The influence of the water level in the period of the open river channel and the duration of lower floodplain inundation on the feeding conditions, abundance, and population state of coregonids in the Lower Ob was investigated. The long-term dynamics of catches of some coregonid species was analyzed and compared with changes in the hydrologic conditions in the floodplain. The relationship between basic hydrologic conditions in the Lower Ob (water level in the period of the open channel, the duration of the lower floodplain inundation), the coregonid population sizes, the state of spawners, and the size of catches is demonstrated.     

武汉市重污染行业发展及严格环境管理对策建议研究

重污染行业作为地方经济的助推器，一直都是区域行业调整的众夭之的。只有从严区域环境管理才能兼得“工业倍增”与生态文明建设之利。武汉市作为典型的工业城市，化工、制药等重污染行业因其类别多、规模化程度低、排污量较大、空间发展无序已成为环境管理的难点。贯彻新环保法体系及十八大精神，从严环境准入前置门槛、科学统筹空间布局规划、规范环境监管与执法、实施诚信档案市场倒逼，是促进工业城市的生态文明发展的可靠途径。     

An Ecophysiological Study of Plants Growing on the Fly Ash Deposits from the “Nikola Tesla–A” Thermal Power Station in Serbia

This ecophysiological research on the ash deposits from the Nikola Tesla–A thermal power station in Serbia covered 10 plant species (Tamarix gallica, Populus alba, Spiraea van-hauttei, Ambrosia artemisifolia, Amorpha fruticosa, Eupatorium cannabinum, Crepis setosa, Epilobium collinum, Verbascum phlomoides, and Cirsium arvense). This paper presents the results of a water regime analysis, photosynthetic efficiency and trace elements (B, Cu, Mn, Zn, Pb, and Cd) content in vegetative plant parts. Water regime parameters indicate an overall stability in plant-water relations. During the period of summer drought, photosynthetic efficiency (Fv/Fm) was low, ranging from 0.429 to 0.620 for all the species that were analyzed. An analysis of the tissue trace elements content showed a lower trace metal concentration in the plants than in the ash, indicating that heavy metals undergo major concentration during the combustion process and some are not readily taken up by plants. The Zn and Pb concentrations in all of the examined species were normal whereas Cu and Mn concentrations were in the deficiency range. Boron concentrations in plant tissues were high, with some species even showing levels of more than 100 g/g (Populus sp., Ambrosia sp., Amorpha sp., and Cirsium sp.). The presence of Cd was not detected. In general, it can be concluded from the results of this research that biological recultivation should take into account the existing ecological, vegetation, and floristic potential of an immediate environment that is abundant in life forms and ecological types of plant species that can overgrow the ash deposit relatively quickly. Selected species should be adapted to toxic B concentrations with moderate demands in terms of mineral elements (Cu and Mn).     

Predicting the Thermal Effects of Dam Removal on the Klamath River

The Klamath River once supported large runs of anadromous salmonids. Water temperature associated with multiple mainstem hydropower facilities might be one of many factors responsible for depressing Klamath salmon stocks. We combined a water quantity model and a water quality model to predict how removing the series of dams below Upper Klamath Lake might affect water temperatures, and ultimately fish survival, in the spawning and rearing portions of the mainstem Klamath. We calibrated the water quantity and quality models and applied them for the hydrometeorological conditions during a 40-year postdam period. Then, we hypothetically removed the dams and their impoundments from the models and reestimated the rivers water temperatures. The principal thermal effect of dam and reservoir removal would be to restore the timing (phase) of the rivers seasonal thermal signature by shifting it approximately 18 days earlier in the year, resulting in river temperatures that more rapidly track ambient air temperatures. Such a shift would likely cool thermal habitat conditions for adult fall chinook (Oncorhynchus tshawytscha) during upstream migration and benefit mainstem spawning. By contrast, spring and early summer temperatures could be warmer without dams, potentially harming chinook rearing and outmigration in the mainstem. Dam removal might affect the rivers thermal regime during certain conditions for over 200 km of the mainstem.     

FLUVIAL GEOMORPHOLOGICAL METHODOLOGY FOR NATURAL STABLE CHANNEL DESIGN1

A fluvial geomorphological methodology for designing natural stable channels is being widely applied for river restoration. It is an analogue procedure, as the W/d ratio and sinuosity from a reference reach are scaled to determine the restoration design. The choice of reference reach is crucial and published criteria specify that it should be stable, correspond to the stream type at the restoration site, have the same valley type, and be from the same hydrophysiographic region. For stable, meandering gravel cobble bed rivers flowing through alluvial flood plains (C3 and C4 stream types), UK regime equations are used to evaluate the procedure. Successful design requires particular combinations of the ratios of bankfull discharge, bed material size and load, valley slope, and bank vegetation category between the reference and restoration sites. These critical ratios, which are confirmed by U.S. field data, provide guidelines for selecting a suitable reference reach for C3‐C4 stream types. They also indicate that the reference reach can be in any valley type or hydrophysiographic region. The geomorphological procedure will apply to all stable stream types, provided the reference reach is correctly identified. Specific guidelines for each stream type await the development of additional regime equations.     

基于MATLAB分析的城市道路照明环境比

基于驾驶员在行驶过程中的注意力大部分集中在车辆的正前方,忽略了道路两侧的情况的视觉特性,更容易引发交通事故的问题。环境比为评价路边物体可视度的指标,为了保证评价的准确性,尤其是保障夜间行驶的良好视觉环境,可以根据路灯设置的基本原则及照明强度与可见度的关联特性,使用MATLAB(矩阵实验室)对环境比进行模拟分析,从理论的角度研究其相关的影响因素,提出了采取减小灯具倾斜角、缩短灯具悬臂悬挑长度以及增加路灯灯杆安装位置与路缘石的距离等措施可以提高道路照明环境比的观点,可以作为路灯改造工程、路灯灯具外形的设计以及夜间行驶事故分析的理论基础。     

Complex dynamics in the uptake of new farming practices: a case study for organic waste application

Adverse environmental effects of intensive agriculture, together with scarcity in phosphates and water, urge farmers to find more sustainable practices. An example of such a sustainable practice is on-farm processing of organic waste. This paper explores three mechanisms that can lead to a widespread uptake of this technique: (1) economies of scale, (2) information sharing, and (3) adjustment of social norms. Although each of these mechanisms has been studied before, this paper provides new insights by considering the interactions that might exist between the different mechanisms when they are applied to real-life situations. Based on a pilot study, we developed a multi-criteria mathematical programming model at individual farm level. We used this model to simulate the uptake of on-farm processing of organic waste, as a result of the three mechanisms and their interactions. Our results show that each mechanism results in an increased uptake, but is not likely to cause a widespread uptake. Interaction between the mechanisms, will lead to a much higher uptake. This result suggests that simultaneous consideration of multiple mechanisms is essential to understand the behaviour of social–ecological systems.     

Assessment of predation risk via illumination level: facultative central place foraging in the cricetid rodent Phyllotis darwini

It is well known that the risk of predation affects prey decision making. However, few studies have been concerned with the cues used by prey to assess this risk. Prey animals may use indirect environmental cues to assess predation hazard since direct evaluation may be dangerous. I studied the assessment of predation risk, manipulated via environmental illumination level, and the trade-off between foraging and predation hazard avoidance in the nocturnal rodentPhyllotis darwini (Rodentia: Cricetidae). In experimental arenas I simulated dark and full moon nights (which in nature correlate with low and high predation risk, respectively) and measured the immediate responses of animals to flyovers of a raptor model. Second, varying illumination only, I evaluated patch use, food consumption, central place foraging, and nocturnal variation of body weight. During flyover experiments, animals showed significantly more evasive reactions under full moon illumination than in moonless conditions. In the patch use experiments, rodents significantly increased their giving-up density and decreased their total food consumption under moonlight. On dark nights, rodents normally fed in the food patch, but when illumination was high they became central place foragers in large proportion. Moreover, the body weight of individuals decreased proportionately more during bright nights. These results strongly suggest thatP. darwini uses the level of environmental illumination as a cue to the risk of being preyed upon and may sacrifice part of its energy return to avoid risky situations.